1. Field of the Invention
The present invention relates to a gelatinous composition, especially suitable for external use.
2. Description of the Related Art
Silicone oil is formulated in a wide variety of commercial products including make-up cosmetics, scalp and hair cosmetics from the characteristics thereof, such as the light spreadability and the refreshing feeling at the time of use. Silicone oil is especially used, with effecting the characteristics, in gelatinous products such as gelatinous foundations, sun screen gels, moisture gels, hair gels, antiperspirant gels.
As gelatinous compositions, a gelatinous composition containing 2-30 parts by weight of dextrin fatty acid esters in 100 parts by weight of silicone oil (JP-B-3-6179), gelatinous compositions containing organohydrogen polysiloxanes and low viscosity silicone oils (JP-A-63-152308), etc have been proposed.
However, these known gelatinous compositions containing silicone oil have problems of poor stability with the elapse of time and the separation of silicone oil.
Recently, although gelatinous cosmetic compositions containing silicone oil having excellent stability with the elapse of time have been proposed (see Japanese Patent Application No. 5-268168) (i.e., JP-A-7-100358), it is pointed out that some stickiness is felt and dewiness is insufficient at the time of use.
Accordingly, the object of the present invention is to provide a gelatinous composition containing silicone oil having an excellent stability with the elapse of time and having feelings of little stickiness and dewiness at the time of use.
The present inventors engaged in intensive research with the purpose of solving the above-mentioned problems and, as a result, found that the above-mentioned problems can be solved by formulating special silicone compounds and lower alcohols, whereby the present invention has been completed.
That is, in accordance with the present invention, there is provided a gelatinous composition comprising:
(i) at least one silicone oil,
(ii) at least one polyether-modified silicone having the formula (I): 
wherein A independently represents a group selected from the group consisting of a methyl group, phenyl group and polyoxyalkylene group having the formula (II):
xe2x80x94C3H6O(C2H4O )a(C3H6O)bRxe2x80x2xe2x80x83xe2x80x83(II)
wherein Rxe2x80x2 is a group selected from the group consisting of a hydrogen atom, an acyl group and alkyl groups having 1 to 4 carbon atoms, a and b are independently an integer of 0 to 50, provided that both a and b are not zero,
R independently represents a methyl group or phenyl group,
m is an integer of 1 to less than 50 and n is an integer of 1 to 40,
provided that a part of the methyl group, phenyl group and polyoxyalkylene group may be substituted with a fluorine atom, and at least one polyoxyalkylene group is present in one molecule,
(iii) water, and
(iv) at least one lower alcohol.
In a gelatinous composition according to the present invention, especially, when the content of the lower alcohol is 1.0 to 25.0% by weight, based upon the total amount of the composition, when the lower alcohol is ethanol or isopropanol, or when the silicone oil is cyclic dimethylpolysiloxane, the desired advantageous effects can be obtained.
The mode of carrying out the present invention will now be explained.
The gelatinous compositions of the present invention are those containing one or more silicone oils.
The silicone oils formulated in the gelatinous composition of the present invention are not specifically limited and include, for example, low to high viscosities diorganopolysiloxanes such as dimethyl polysiloxane, methylphenyl polysiloxane, dimethylsiloxane methylphenylsiloxane copolymer; cyclic polysiloxane such as octamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane, tetramethyl tetraphenyl cyclotetrasiloxane; cyclic siloxane solutions of gum-like dimethyl polysiloxanes, gum-like dimethylsiloxane methylphenyl siloxane copolymer, gum-like dimethylpolysiloxane, etc., having high degree of polymerization; cyclic siloxane of trimethylsiloxy silicic acid, trimethylsiloxy silicic acid, etc. and further include, for example, diorgano polysiloxane having a C6-C50 alkyl group, amino-modified silicone, alkyl-modified silicone, fluorine-modified silicone etc.
Among these, cyclic polysiloxanes, especially cyclic dimethylpolysiloxanes such as octamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane, etc. are preferable to provide the gelatinous composition having an extremely excellent stability with the elapse of time.
Although the content of the silicone oil in the gelatinous composition of the present invention is not specifically limited, the preferable content is 80% by weight or less. When the content is more than 80% by weight, the stability of the gel with the elapse of time tends to become poor.
The gelatinous composition of the present invention further contains one or more polyether-modified silicone having the above-mentioned formula (I). This polyether-modified silicone (I) is an organopolysiloxane having at least one polyoxyalkylene group in one molecule thereof.
In the formula (I), A independently represents a methyl group, phenyl group or polyoxyalkylene group having the formula (II).
xe2x80x94C3H6O(C2H4O)a(C3H6O)bRxe2x80x2xe2x80x83xe2x80x83(II)
In the formula (II), a hydrogen atom, an acyl group or an alkyl group having 1 to 4 carbon atoms. Examples of the acyl group of Rxe2x80x2 are a formyl group, acethyl group, propionyl group, butyryl group, acryloyl group, benzoyl group, toluoyl group. Examples of the alkyl group having 1 to 4 carbon atoms are a methyl group, ethyl group, i-propyl group, n-propyl group, t-butyl group, n-butyl group.
Furthermore, a and b are independently an integer of 0-50, provided that both a and b are not zero. When both a and b are zero, unpreferably, the polyether-modified silicone does not exhibit the sufficient viscosity increasing or thickening effect. When a and/or b are more than 50, the resultant gelatinous composition exhibits the unpreferable stickiness feeling at the time of use.
In the formula (I), m is an integer of 1 to less than 50, preferably 5 to 48 and n is an integer of 1 to 40. When m is zero and/or n is zero, unpreferably, the resultant polyether-modified silicone does not exhibit the sufficient thickening effect. On the other hand, when m is not less than 50 and/or n is more than 40, the resultant gelatinous composition unpreferably provides the stickiness feeling at the time of use.
Example of the methyl group, a part of which is substituted with a fluorine atom are a fluoromethyl group, difluoromethyl group, etc and examples of the phenyl group, a part of which is substituted with a fluorine atom is a fluorophenyl group, etc.
Although the content of the polyoxyalkylene group (II) in the polyether-modified silicone (I) is not specifically limited, the preferable content is 40 to 55% by weight and the especially preferable content is 40 to 50% by weight. When the content of the polyoxyalkylene group is less than 40% by weight, the thickening effect of the resultant polyether-modified silicone tends to be unpreferably remarkably decreased. Contrary to this, when the content is more than 70% by weight, the compatibility with the silicone oil tend to be unpreferably decreased and also the thickening effect tends to be unpreferably decreased.
Further, there are no specific limitations to the molecular weight and the viscosity at 25xc2x0 C. of the polyether-modified silicone (I) formulated in the gelatinous composition of the present invention, but the preferable weight-average molecular weight is 20,000 to 80,000.
In the present gelatinous composition, although there are no specific limitation to the content of the polyether-modified silicone (I), the content is preferably 2 to 50% by weight, more preferably 5 to 40% by weight, based upon the total amount of the composition. When the content of the polyether-modified silicone is less than 2% by weight, based upon the total weight of the composition, the formation of the stable gelatinous composition tends to be unpreferably difficult, whereas when the content is more than 50% by weight, the resultant gelatinous composition tends to unpreferably possess the stickiness feeling at the time of use.
The present gelatinous composition further contains water. Although the content of the water in the present gelatinous composition is not specifically limited, the content is preferably 0.2 to 80% by weight, more preferably, 10 to 40% by weight, based upon the total amount of the composition. When the content of water is less than 0.2% by weight of the total weight of the composition, the sufficiently stable gelatinous composition tends to be unpreferably difficult. Contrary to this, when the content of the water is more than 80% by weight, the resultant gelatinous composition tends to be unpreferably easily separated from the water, and therefore, the formation of the sufficiently stable gelatinous composition tends to be unpreferably difficult.
The present gelatinous composition further contain one or more lower alcohols.
Although the kinds of the lower alcohols usable in the present gelatinous composition are not specifically limited, the use of those having 1 to 4 carbon atoms, such as methanol, ethanol, i-propanol, n-propanol, t-butanol, sec-butanol, etc. is preferable. These lower alcohols have the effect to remarkably improve the stability of the gelatinous composition with the elapse of time. Among these lower alcohols, the use of ethanol and i-propanol, especially ethanol, is preferable.
The content of the lower alcohols in the present gelatinous composition is preferably 1 to 25% by weight, more preferably 5 to 10% by weight, based upon the total amount of the composition. When the content of the lower alcohols based upon the total weight of the composition is less than 1% by weight or more than 25% by weight, the stability of the resultant gelatinous composition with the elapse of time is unpreferably decreased.
In the gelatinous composition of the present invention, in addition to the above-mentioned essential ingredients, it is possible to formulate therein components conventionally used in the gelatinous compositions such as a humectant, surfactant, ultraviolet (U.V) absorber, antioxidant, preservative, antifungal agent, drug, extender pigment, coloring pigment, fragrance etc, so long as the intended effects of the present invention are not impaired.
The gelatinous composition of the present invention can be advantageously used in the fields of drugs, quasi-drugs or cosmetics, especial external use thereof. The present gelatinous composition may be used as, for example, a gelatinous foundation, sun screen gel, moisture gel, gelatinous cosmetic base, cleaning or make-up removal gel, hair gel, antiperspirant gel, etc.